We're seeing high system load and decreased performance on our
production Gerrit instance. Some research suggests this may be I/O
contention which can be relieved through better caching:
https://groups.google.com/g/repo-discuss/c/7CemrH4lVJE
According to `gerrit show-caches --show-jvm --show-threads` some of
our memory-only caches are already at their default maximums after
only a few days of operation, and one in particular
(changeid_project) has a particularly poor cache hit ratio of 24% at
the moment. Increase changeid_project from the 1024 entry default by
32x (manual tests at 8x approached 50% cache hit), increase projects
by 4x (greater than the number of repos we host for now), and double
the others (groups_bysubgroup, permission_sort) since they still had
reasonable cache hit ratios while full. Also alpha-order the
existing cache overrides in our config for improved maintainability.
This will require a Gerrit service restart to take effect, once the
file update has been deployed.
Change-Id: Ieecd1802ce53cc0d37c68476b94b44cbe36fbd6e
835122560f